Chess Opening Theory/1. e4/1...e5/2. f4

King's Gambit

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Common moves:
2...exf4 - King's Gambit Accepted
2...Bc5 - King's Gambit Declined
2...d5 - Falkbeer Countergambit

King's Gambit

White attacks black's pawn on e5 with their f-pawn, but the pawn on f4 is attacked and undefended. A gambit - which is not the same thing as an opening - involves a sacrifice of material (chess pieces, usually pawns) for positional gain. In this case, White seeks to tempt Black's pawn away from the centre onto f4, which would give White the freedom to play d4 and e5. The move d4 will then uncover an attack by the c1-bishop on Black's f4-pawn, and Black will have to make further non-developing moves to retain it.

Unfortunately for White, after Black accepts the gambit with

• 2...exf4,

King's Gambit

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Ouch.

White cannot yet play 3.d4. This is because the move 2.f4 also weakens the e1-h4 diagonal, and 2...exf4 weakens it further by controlling the g3 square. Black can therefore respond with 3...Qh4+! and since White cannot play 4. g3 due to the Black pawn on f4, White's king is forced out to the second rank in the opening, leaving Black with a better position (diagram left). 2...exf4 is considered best in high-level chess, but Black must defend accurately.

It's also possible for Black to decline the gambit.

• 2...Bc5 is the usual way of doing so, taking advantage of the fact that Black's e-pawn isn't really threatened (3.fxe5? gets hit by 3...Qh4+! again). Black makes sure that White won't be able to play d4 or to castle kingside without going to some considerable effort to shift the bishop from its new diagonal.
• 2...d5 gives the position a different flavour. Normally Black only manages to get in one of the moves ...e5 and ...d5 this early in the opening, but since 2.f4 did nothing to prevent ...d5, why not play it now? Since it attacks the undefended e-pawn, Black will still get to take one of White's pawns if she wants to.
• Black could also reasonably play 2...Nc6, a variation that is rarely explored.

Theory table

For explanation of theory tables, see theory table and for notation, see algebraic notation.

1.e4 e5 2.f4

	2	3	4	5	6	7
King's Gambit Accepted	f4 exf4	Nf3 g5	h4 g4	Ne5 Nf6	d4 d6	Nd3 Nxe4	∞
King's Gambit Declined	... Bc5	Nf3 d6	Nc3 Nf6	Bc4 Nc6	d3 Bg4	Na4 O-O	+/=
Falkbeer Countergambit	... d5	exd5 c6	Nc3 exf4	Nf3 Bd6	d4 Ne7	Bc4 O-O	+/=
King's Gambit Declined	... d6	Nf3	+/=
	... Nc6	Nf3 f5	exf5 e4	Ne5 Nf6	d3 Qe7	dxe4 Nxe4	∞
Panteldakis Countergambit	... f5	exf5	+/=
Norwalde Variation	... Qf6?!	+/=
Keene Defence	... Qh4+?!	g3 Qe7	+/=

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References

• Nunn's Chess Openings. 1999. John Nunn (Editor), Graham Burgess, John Emms, Joe Gallagher. ISBN 1-8574-4221-0.

• Kasparov, Garry, & Keene, Raymond 1989 Batsford chess openings 2. ISBN 0-8050-3409-9.